Speed control device



United States Patent f 3,400,697 SPEED CONTROL DEVICE Carl Cupit,Plainiield, Christopher J. Oliva, Chicago,

Charles Broad, Jr., Westchester, and Ralph A. Gritehen,

Park Forest, 11]., assignors to International Harvester Company, acorporation of Delaware Filed Dec. 23, 1964, Ser. No. 420,558 6 Claims.(Cl. 123-97) This invention relates to engine speed control devices.More particularly, the invention relates to speed control devices of acentrifugal type used to vary the quantity of fuel and air supplied toan engine in response to changes in engine load or in response tochanges in position of an associated speed control lever.

One problem associated with conventional centrifugal speed controldevices relates to providing sensitive controls that are responsive tosmall speed changes at relatively low engine speeds.

Thus, an object of this invention is to provide an improved speedcontrol device.

Another object is to provide a centrifugal speed control device that isresponsive to small changes in engine speed from a selected engine speedwithin a low to intermediate speed range.

A further object of the invention is to provide a speed control deviceof the centrifugal type having two springs opposing centrifugal actionof flyweights including a weaker spring that senses and responds tosmall changes in engine speed at low and intermediate engine speeds.

Still another object of the invention is to provide a centrifugal enginespeed control device having auxiliary spring means that is responsive tosmall changes in engine speed at low and intermediate speeds as well asa primary spring that is operative for regulating engine speeds atintermediate to high operating speeds to enable accurate speed selectionthroughout tht range of low to high engine speeds.

These and other objects of the invention will become apparent from thefollowing description when considered in conjunction with theaccompanying drawing, wherein:

FIG. 1 is a somewhat diagrammatic view in section of a speed controldevice constructed in accordance with the principles of the presentinvention;

FIG. 2 is a sectional view of a portion of the device shown in FIG. 1with a speed selection lever shown in a different position.

Referring to the drawing, there is shown a speed control device orgovernor 10 for an associated engine, not shown, including anengine-driven governor shaft 12 secured within a governor pinionassembly 14 and having a governor weight carrier 16 secured theretoserving as a pivotal support for a pair of governor weights orflyweights 18 which rotate with the shaft.

The driven shaft 12 supports a thrust sleeve assembly 20 including asleeve 22 and ball :bearing 23 for rotation as well as axial slidingmovement on the shaft 12 toward and away from the pinion assembly 14.

The fiyweights 18 each have an inwardly extending finger 24 extendinginwardly toward a center of rotation 26 of the shaft 12 and adapted toengage one end 28 of the sleeve adjacent the pinion assembly 14. Duringoperation of the engine, the flyweights 18 tend to swing pivotallyoutwardly with respect to the shaft center of rotation 26, as indicatedby the arrows. As the flyweights swing outwardly, the fingers 24 movepivotally to the right, as viewed in the drawing, urging the sleeve 22to the right.

The speed control device 10 includes a housing 30 and speed change levermeans 32 including a forked arm 33 positioned against the ball "bearing23 biasing it to the left and a body portion 35 pivotally secured3,400,697 Patented Sept. 10, 1968 "ice to the housing and connected toconventional fuel throttling mechanism, not shown, to vary the quantityof fuel supplied to the engine. The speed control device 10 alsoincludes a speed selection lever 34 pivotally mounted on the housing toselectively change the speed of the engine and a leaf type cantileveredspring assembly 36 secured to the speed selection lever 34 for move mentwith the speed selection lever 34 upwardly and downwardly as viewed inthe drawings about a center of rotation 38. The spring assembly 36includes a mounting base 37 which is secured to lever 34 and a leafspring 39 which is cantilevered outwardly from the mounting base 37 andwhich has a far end 40 having an opening, not shown, therein forconnective receipt of a looped end 42 of a governor coil spring 44connected at its other end 46 to the speed change lever 32 and urgingthe speed lever 32 to move in a counterclockwise direction about acenter of rotation 47 toward an increased :fuel position to increase thespeed of the associated engine.

The leaf spring 39 is a relatively softer or weaker spring in comparisonto the relatively stronger coil spring 44 and hence spring 39 is moresensitive to small changes in position of the speed change lever 32.Accordingly, spring 39 is adapted to regulate low and intermediateengine speeds below a predetermined speed; and the relatively strongercoil spring 44 is adapted to regulate the higher engine speeds above thepredetermined speed.

The speed selection lever 34 has an upper surface 48 which is adapted toengage or support a lower surface 50 of the leaf spring when speedselection lever 34 is moved to a predetermined upper position for higherengine speeds as illustrated in FIG. 2.

Having now described the invention, its operation should be clear. Theengine speed regulation device 10 incorporates engine actuatedcentrifugal goveinor weights 18 which act on speed change lever 32 tothrottle the amount of fuel supplied to the engine. With increases inrotational shaft speed, the governor weights force thrust sleeve 22 tothe right, as viewed in the drawing, against speed change lever means 32to rotate it clockwise, decreasing fuel supplied to the engine.Resilient means comprising a first governor spring 44 opposes the actionof the flyweights by urging the speed change lever 32 counterclockwisetoward a full or relatively increased fuel position. Second resilientmeans comprising a relatively weaker governor spring connected to lever34 and adapted to rotate with it, cooperates with the first spring toassist it in opposing the action of the flyweights in rotating the speedchange lever 32 clockwise.

To increase engine speed, the speed selection lever 34 is raised, movingthe two springs upwardly and rotating speed change lever means 32counterclockwise in fuel increasing direction to urge the thrust sleeve22 to the left tending to collapse the governor weights. The increasedfuel supplied to the engine tends to increase the speed of the rotatingshaft 12 and the governor weights 18 I0- tate outwardly from the shaftto a predetermined spring balancing point at which point the thrust ofthe governor fingers to the right against the sleeve 22 is equal to theforce of the springs urging the sleeve to the left; at this point thespeed of the engine is stabilized, as is well understood.

The one spring is relatively weaker than the other spring and isconsequently more sensitive to and more responsive to small speedchanges in the relatively lower speed ranges; hence the softer of thetwo springs regulates the speed change lever at low and medium rangespeeds. As engine speed is increased by raising the speed selectionlever 34, spring tension increases and both springs operate to resistthe action of the flyweights in moving the speed change lever toward adecreased fuel position. At a predetermined raised positon of the speedselection lever 34 to achieve a predetermined speed, means are providedfor rendering the weaker spring ineffective, that is, the speedselection lever 34 moves into a spring supporting position and thereactive effect of the weaker spring is completely expended. Thus, theweaker of the two springs is rendered ineffective above a predeterminedrelatively higher engine speed; and control of speeds higher than thispredetermined speed are governed by the stronger of the two springs.

Accordingly, the unique spring tensioning mechanism of the presentinvention achieves a centrifugal speed control device which is sensitiveto and responsive to small speed changes throughout a wide speed rangefrom low to high speeds.

Since modifications of the details of the structure as illustrated arecontemplated, the invention should be limited only by the scope of theappended claims. The invention is claimed as follows:

1. In a centrifugal governor including a housing, a fuel control member,engine actuated centrifugal flyweights acting on said member to move ittoward a lower fuel position, a first governor spring o posing theaction of the flyweights said spring having first and second ends, saidfirst end being connected with said fuel control member to urge ittoward a fuller fuel position, said second end being connected to saidhousing, the improvement comprising: a second governor springinterconnected directly to said second end of said first governor springand said housing and adapted to cooperate with said first governorspring in opposing the action of the flyweights, said second governorspring being relatively weaker than said first governor spring and beingadapted to oppose the action of said flyweights; and stop means torender said second governor spring ineffective when said memberapproaches a predetermined position corresponding to a predeterminedengine speed.

2. In a device for controlling the delivery of fuel to an engine to becontrolled and being sensitive to the speed of said engine and having:

a governor shaft rotating at an engine related speed;

a thrust sleeve positioned on said shaft and rotating therewith, saidthrust sleeve being adapted for sliding movement axially on said shaft;

a fuel control member adapted to be engaged by said sleeve when it ismoved axially in one direction n said shaft;

governor Weights pivotally connected to said rotating shaft, each ofsaid Weights having a radially 1nwardly extending finger adapted toengage said sleeve, said weights being adapted to swing radiallyoutwardly with increases in the speed of said rotating shaft, saidfingers being adapted to move said sleeve axially away from said shaftagainst said fuel control member to move it toward a position todecrease the fuel supplied to said engine;

resilient spring means opposing the action of the flyweights andconnected with said fuel control member to increase the fuel supply tosaid engine;

and speed selection means to vary the effective force of said resilientspring means in opposing the action of the flyweights to vary the enginespeed, the improvement comprising:

second resilient spring means having first and second ends and beingconnected at its first end to said speed selection lever and beingconnected at its second end to said first resilient spring means, saidsecond resilient spring means being adapted for movement upwardly anddownwardly with said speed selection lever to vary the effective springforce opposing the outwardly swinging action of the flyweights, saidsecond resilient means being relatively weaker than said first resilientmeans, said speed selection means having spring rest means thereonadapted to support said second resilient spring means and render itineffective when said speed selection means is moved to a predeterminedposition corresponding to a predetermined intermediate engine speed.

3. In a device for controlling the delivery of fuel to an engine andbeing sensitive to the speed of the engine, said device having:

a governor shaft rotating at an engine related speed;

a thrust sleeve supported on said shaft and rotating therewith, saidthrust sleeve being adapted for sliding movement axially on said shaft;

a fuel control member adapted to be engaged by said sleeve when it ismoved axially in one direction;

governor weights pivotally secured to said rotating shaft, each of saidWeights having a radially inwardly extending finger adapted to engagesaid sleeve, said weights being adapted to swing radially outwardly withincreases in the speed of said rotating shaft, said fingers beingadapted to move said sleeve in said one direction against said fuelcontrol member to move it into a position to decrease the fuel suppliedto said engine;

a coil spring opposing the action of the flyweights, said coil springhaving two ends and being connected at one end to said fuel controlmember to increase the fuel supplied to said engine;

and rotatable speed selection means to vary the effective force of saidcoil spring in opposing the action of the flyweights, the improvementcomprising:

a leaf spring secured at its one end to said speed selection means incantilevered fashion for rotation with said speed selection means andconnected at its other end to a second end of said coil spring, saidleaf spring being adapted for rotation with said speed selection meansto vary the spring force opposing the outwardly swinging action of theflyweights, said leaf spring being relatively weaker than said coilspring, said speed selection means having spring rest means thereonadapted to support said leaf spring between the ends of said spring andrender it ineffective when said speed selection means is moved to apredetermined position corresponding to a predetermined intermediateengine speed.

4. In a device for controlling the delivery of fuel to an engineincluding a fuel control member, engine actuated centrifugal flyweightsacting on said member to move it toward a position to decrease theamount of fuel supplied to said engine, a first governor spring opposingthe action of the flyweights and connected to said member to urge it toincrease the amount of fuel supplied to said engine, the improvementcomprising: a second governor spring connected to said first governorspring and cooperating therewith, said second governor spring being arelatively weaker spring than said first governor spring; and means torender said second governor spring ineffective at a preselected enginespeed, whereby engine speeds below a predetermined engine speed areregulated by said second governor spring and whereby engine speeds abovea predetermined speed are governed by said first governor spring.

'5. In a selectively variable constant speed governor for an engineincluding a shaft rotating at an enginerelated speed, fuel control meansto control the fuel delivered to the engine, governor weights pivotallyconnected to said shaft and adapted to engage said fuel control means tourge said fuel control means to decrease the amount of fuel supplied tosaid engine as the speed of said engine shaft increases, first springmeans connected to said fuel control means acting on said fuel controlmeans to increase the amount of fuel supplied to said engine, speedselection means connected to said spring means and adapted for movementto vary the tensile force of said spring means acting in opposition to acentrifugal action of said weights, the improvement comprising: secondspring means connected to said first spring means and cooperatingtherewith, said second spring means being relatively weaker than saidfirst spring means and adapted to oppose the action of said governorweights at relatively lower engine speeds, said second spring meansbeing of the leaf type and being secured in cantilevered position tosaid speed selection means for movement therewith, said speed selectionmeans including means to render said second spring means ineffectivewhen said speed selection means is moved into a predetermined positionto achieve a predetermined engine speed, whereby said second springmeans governs the speed of said engine at relatively lower engine speedsand said first spring means governs the speed of said engine atrelatively higher engine speeds.

6. In an engine governor including a fuel control member, engineactuated centrifugal fiyweights acting on said member to move it towarda position to decrease the amount of fuel supplied to said engine, acoil spring connected to said fuel control member opposing the action ofsaid flyweights and urging said fuel control member to a position toincrease the amount of fuel supplied to said engine, and a speedselection lever to vary the position of said fuel control member, theimprovement comprising: a leaf spring having two ends and being securedat a first end to said speed selection lever for movement therewith witha second end cantilevered therefrom, said leaf spring being connected atits second end to said coil spring, said speed selection lever beingadapted to render said leaf spring ineffective when said speed selectionlever is moved to a position corresponding to a predeterminedintermediate fuel position of said fuel control member, said leaf springbeing relatively weaker than said coil spring whereby said leaf springacts to govern the speed of said engine at relatively lower enginespeeds and said coil spring acts to govern the speed of said engine atrelatively higher engine speeds.

References Cited UNITED STATES PATENTS 1,325,478 12/1919 Krebs 73-5462,507,689 5/1950 Buck 73-537 RALPH D. BLAKESLEE, Primary Examiner.

1. IN A CENTRIFUGAL GOVERNOR INCLUDING A HOUSING, A FUEL CONTROL MEMBER,ENGINE ACTUATED CENTRIFUGAL FLYWEIGHTS ACTING ON SAID MEMBER TO MOVE ITTOWARD A LOWER FUEL POSITION, A FIRST GOVERNOR SPRING OPPOSING THEACTION OF THE FLYWEIGHTS SAID SPRING HAVING FIRST AND SECOND ENDS, SAIDFIRST END BEING CONNECTED WITH SAID FUEL CONTROL MEMBER TO URGE ITTOWARD A FULLER FUEL POSITION, SAID SECOND END BEING CONNECTED TO SAIDHOUSING, THE IMPROVEMENT COMPRISING: A SECOND GOVERNOR SPRINGINTERCONNECTED DIRECTLY TO SAID SECOND END OF SAID FIRST GOVERNOR SPRINGAND SAID HOUSING AND ADAPTED TO COOPERATE WITH SAID FIRST GOVERNORSPRING IN OPPOSING THE ACTION OF THE FLYWEIGHTS, SAID SECOND GOVERNORSPRING BEING RELATIVELY WEAKER THAN SAID FIRST GOVERNOR SPRING AND BEINGADAPTED TO OPPOSE THE ACTION OF SAID FLYWEIGHTS; AND STOP MEANS TORENDER SAID SECOND GOVERNOR SPRING INEFFECTIVE WHEN SAID MEMBERAPPROACHES A PREDETERMINED POSITION CORRESPONDING TO A PREDETERMINEDENGINE SPEED.